About: consistent hashing

Transcript

1. ӋԍӏӑӞԍӠӧӜӏӾʂҍ҅ѥ҈
   ӬӆӏӮװɒױґҭѭѷҵ
   

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2. ѵѵ҉ѥѧӧӜӏԍӇҊґ
   

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3. Ό਺ҐӄـҴΌ਺ҐӦـӡҍðҬƾ҈ҁѥ

   Ҋѥѧī୊
   

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4. ׏ֿ ׏׀ ׏ׁ
   ׏ׅ ׏׆ ׏ׇ ׏ֿ־
   ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ
   ӄـ
   Ӧـӡ
   

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5. ׏ֿ ׏׀ ׏ׁ
   ׏ׅ ׏׆ ׏ׇ ׏ֿ־
   ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ
   ˅૝ˤҍґѵѧҌ҆҈ҝѹѥ
   Ӧـӡ
   

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6. ѵҮѮ҉ѯҭҊ
   ؆!׌ҐӏӼـӟҺԍӇ
   ؆ӄӼӜӏӾҐåࢄشࠓ´҆҈ҭҥ҅
   ؆Ҍҍѭѣҭҥ҅ҴҌҵѭͮѥײѺҍåð
   ……ҊѭҠѣѥүѥүҊ¸ê
   

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7. €˕ӏԍӯԃҌȠʂ
   פӺӐӾԅʂץ
   

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8. ׏ֿ
   ׏׀
   ׏ׁ
   ׏ֿ
   ׏׀
   ׏ׁ
   %3 = 1
   %3 = 2
   %3 = 0
   ׏ׂ %3 = 1
   ӺӐӾԅʂ
   Ӧـӡ਺Ґ৒²ҴҊҭ
   ׏׃
   ׏ׄ
   %3 = 2
   %3 = 0
   

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9. ӺӐӾԅʂ׋
   ؆ÅҬѮχѵҫҌѱ҈ͮѷѿѧ
   ؆ӏԍӯԃ
   ؆ӦـӡҴϟՃѻҭҊѯҍŖő
   

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10. ӺӐӾԅʂ
    ׏ֿ
    ׏׀
    ׏ׁ
    ׏ֿ
    ׏׀
    ׏ׁ
    %3 = 1
    %3 = 2
    %3 = 0
    ׏ׂ %3 = 1
    ׏׃
    ׏ׄ
    %3 = 2
    %3 = 0
    

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11. ӺӐӾԅʂ
    ׏ׂ
    ׏ֿ
    ׏׀
    ׏ׁ
    ׏ֿ
    ׏׀
    ׏ׁ
    %3 = 1
    %3 = 2
    %3 = 0
    ׏ׂ %3 = 1
    ׏׃
    ׏ׄ
    %3 = 2
    %3 = 0
    

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12. ׏ֿ
    ׏׀
    ׏ׁ
    ׏ֿ
    ׏׀
    ׏ׁ
    %4 = 1
    %4 = 2
    %4 = 3
    ׏ׂ %4 = 0
    ӺӐӾԅʂ
    ׏ׂ
    ׏׃
    ׏ׄ
    %4 = 1
    %4 = 2
    ӦـӡҴϟՃѻҭҊѯҍŖő׎׎׎
    ׏׀¦߱ѻқ҈҉ȳѯȈѩѮˠੜ
    

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13. פӺӐӾԅʂץґ
    ࣮ΆѮ؆୯҂ѮӦـӡҐϟՃ؏࡟আѮŖő
    

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14. ӋԍӏӑӞԍӠӧӜӏӾʂ
    • @_LE@YJFYF[@Q׌،TSZLZ[FS[ @ZKLSJ@SE@SETR
    YFFZ׋LZ[YLC\[FE@DKLSJYT[TDTQZITYFQLF_LSJ T[
    WT[ZTS[KF"TYQE"LEF"FC،׮ׇׇֿׅׯ
    • ࣮ΆҊѹ҈ґFRD@DKFEҐҁңҐF[@R@ѮȵĚ

    K[[WZ׋זזJL[K\CאDTRזזPF[@R@
    • SJLSa׍W@DKFY@IILDFY_FYҤ࠾ˉ
    

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15. ӋԍӏӑӞԍӠӧӜӏӾʂ׋
    ؆ӧӜӏӾВ਺ґ€ɠҍåƖѻҭґѼ
    ؆ӧӜӏӾВ਺ҴԂԍӇ…ҍѹ҈࣮Ά
    

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16. ׏ֿ
    ׏׀
    ׏ׁ
    ӋԍӏӑӞԍӠӧӜӏӾʂ

    Ӧـӡ׍ӄـҐѿҮҀҮҴęѺӧӜӏӾ̌БҍࣹӨ
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ӧӜӏӾ̌Б
    

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17. ׏ֿ
    ׏׀
    ׏ׁ
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ӧӜӏӾ̌Б
    ׏ֿ
    ׏׀
    ׏ׁ
    ׏ׂ
    ׏׃
    ׏ׄ
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ӋԍӏӑӞԍӠӧӜӏӾʂ

    Ӧـӡ׍ӄـҐѿҮҀҮҴęѺӧӜӏӾ̌БҍࣹӨ
    

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18. ׏ֿ
    @ZK׮ ׯ
    ׏ֿ
    ׏׀
    ׏ׁ
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ۙѥÃҴબ୒
    ׏ֿ
    ׏׀
    ׏ׁ
    ׏ׂ
    ׏׃
    ׏ׄ
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ֿ˕…ҐÃҴҊҭ
    ؼ
    ӧӜӏӾ̌Б
    ӋԍӏӑӞԍӠӧӜӏӾʂ

    Ӧـӡ׍ӄـҐѿҮҀҮҴęѺӧӜӏӾ̌БҍࣹӨ
    

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19. ӋԍӏӑӞԍӠӧӜӏӾʂ׋
    ؆ӧӜӏӾВ਺ґ€ɠҍåƖѻҭґѼ

    ؕҌҐ҉ÅҫҌѥ
    ؆ȳѯȈҰҭҐґӧӜӏӾ̌БҐ€϶҂ѳҐґѼ

    ؕҌҐ҉ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
    

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20. ׏ֿ
    ׏׀
    ׏ׁ
    ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ӧӜӏӾ̌Б
    ׏ֿ
    ׏׀
    ׏ׁ
    ׏ׂ
    ׏׃
    ׏ׄ
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    

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21. ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
    ӧӜӏӾ̌Б
    ׏ֿ
    ׏׀
    ׏ׁ
    ׏ׂ
    ׏׃
    ׏ׄ
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ׏ֿ
    ׏׀
    ׏ׁ
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ׏ׂ
    @ZK׮ ׯ
    ׏ׂҴϟՃ
    

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22. ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
    ӧӜӏӾ̌Б
    ׏ֿ
    ׏׀
    ׏ׁ
    ׏ׂ
    ׏׃
    ׏ׄ
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ׯ
    ׏ֿ
    ׏׀
    ׏ׁ
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ۙѥÃҴબ୒
    ׏ׂ
    @ZK׮ ׯ
    ȳѯȈҰ҆ҁҐґ׏ׄ҂ѳ׎
    

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23. ӋԍӏӑӞԍӠӧӜӏӾʂ׋
    ؆ÅҫҌѥ
    ؆ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
    
    

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24. ӧӜӏӾ̌Б
    ׏ֿ
    @ZK׮ ׯ
    ˅૝ˤҍґ ؟ֿذ׀׋
    

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25. ˅૝ˤҍґ
    ӧӜӏӾ̌Б
    ׏ֿ
    ׏׀
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׏׀ҴϟՃѻҭҊ
    ؟ֿذ׀׋׃־أ
    

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26. ӧӜӏӾ̌Б
    ׏ֿ
    ׏׀
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׏ׁ
    @ZK׮ ׯ
    ˅૝ˤҍґ ؟׀ذׁ׋׀׃أ
    ׏ׁҴϟՃѻҭҊ
    

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27. ӧӜӏӾ̌Б
    ׏ֿ
    ׏׀
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׏ׁ
    @ZK׮ ׯ
    ׏ׂ
    @ZK׮ ׯ
    ˅૝ˤҍґ ؟ׁذׂ׋׀׃أ
    ׏ׂҴϟՃѻҭҊ
    

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28. ӋԍӏӑӞԍӠӧӜӏӾʂ׋
    ؆ÅҫҌѥ
    ؆ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
    
    

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29. ӋԍӏӑӞԍӠӧӜӏӾʂҐ࣮Ά

    ׮F[@R@ҐńĘׯ
    

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30. # ϋογϡؔ਺͸32bit unsigned intͷϋογϡ஋Λฦ͢

    # CRC32, MD5ͷ্Ґ32bitͳͲͰ࣮૷

    func hash(key string) uint32 { ... }
    # ϊʔυͷϋογϡ஋Λܭࢉ
    for _, node := range nodes {
    # ͻͱͭͷϊʔυຖʹ160ݸͷϋογϡΛܭࢉ
    for i := 0; i < 160; i++ {
    k := fmt.Sprintf(“%s-%d”, node, i)

    

    # ϊʔυ໊ͱϋογϡ஋ͷϖΞΛ௥Ճ
    continuum.add(node, hash(k))
    }
    }
    # ϋογϡ஋Ͱιʔτ͓ͯ͘͠
    sort.Sort(continuum)
    ֿאӦـӡӶӜӯҐܭࢉ
    

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31. ֿאӦـӡӶӜӯҐܭࢉ
    ӧӜӏӾ̌Б
    ׏ֿ
    @ZK׮ ׯ
    ֿ҅ҐӦـӡҍରѹ

    Ό਺ҐӧӜӏӾҴܭࢉ

    ذӧӜӏӾܭࢉҍҩҭÅҬҴЕɦ
    ؕ׮׀־־¿ѱҫѥ҉ůŲׯ
    

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32. # ϋογϡ஋Ͱιʔτ͓͚ͯ͠͹ೋ෼୳ࡧͰ୳ࡧͰ͖Δ

    func search(key string) string {
    v := hash(key)
    i, j := 0, n
    for i < j {
    h := i + (j-i)/2
    if (continuum.values[i] > v) {
    i = h + 1
    } else {
    j = h
    }
    }
    return continuum.nodes[i]
    }
    ׀אӧӜӏӾҐ୳ࡧ
    

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33. ׀אӧӜӏӾҐ୳ࡧ
    ӧӜӏӾ̌Б
    _
    @ZK׮ ׯ
    ׏ֿ
    ׏׀
    ׏ׁ
    @ZK׮
    @ZK׮
    @ZK׮
    ׯ
    ׯ
    ׯ
    ׏ׂ
    @ZK׮ ׯ
    ™å୳ࡧ҉€˕ۙѥӧӜӏӾҴʹŲ
    

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34. ҠҊң

    ׮ӋԍӏӑӞԍӠӧӜӏӾʂׯ
    ؆ÅҫҌѥ

    ؕӧӜӏӾВ਺Ҋѹ҈ґ׃…¯ׁ׀CL[׌ׁ׀׌!؆ֿ̙
    ؆ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ

    ؆࣮ΆҤӏԍӯԃ
    

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